Physicochemical and friccohesity study of glycine, l-alanine and l-phenylalanine with aqueous methyltrioctylammonium and cetylpyridinium chloride from T = (293.15 to 308.15) K

Abstract

Density rho, sound velocity u, viscosity eta, apparent molar volume V-phi, isentropic compressibility kappa(s), and apparent molar isentropic compressibility kappa(s,phi) of glycine, L-alanine and L-phenylalanine: (0.05 to 0.15 mol . kg(-1)) with water, 0.002 mol . kg(-1) aqueous methyltrioctylammonium chloride (MTOAC) and cetylpyridinium chloride (CPC) are reported at T = (293.15, 298.15, 303.15 and 308.15) K. The data were regressed against composition and regression constants: apparent molar volume at infinite dilution V-phi(0), apparent molar isentropic compressibility at infinite dilution kappa(0)(s,phi) and viscosity B-coefficient are studied. Surface tension gamma and friccohesity sigma data were calculated from density, pendant drop number and viscous flow time. The V-phi(0) values are found as V-phi(gly,l-phal with water)(0) < V-phi(gly,l-phal with surfactatnt)(0), V-phi(l-ala with surfactatnt)(0) < V-phi(l-ala with water)(0) and kappa(0)(s,phi) values as kappa(0)(phi(gly,l-phal with water)) < kappa(0)(phi(gly,l-phal with surfactatnt)), kappa(0)(phi(l-ala with surfactatnt)) < kappa(0)(phi(l-ala with water)). Surface tension of the solvents are found as water > CPC > MTOAC. Amino acids with surfactants have produced higher friccohesity than with water whereas the friccohesity of amino acids with water and surfactants is found as L-phal > L-Ala > gly over the entire temperature range but with CPC at T = 298.15 K, the order is L-phal > gly > L-Ala. The variations in physicochemical data with temperature and composition inferred structural changes with stronger solute-solvent interactions. (c) 2013 Elsevier Ltd. All rights reserved.